All technical data sheets? Perhaps. Zeiss once
measured the resolving power of various films (Camera Lens News 19,
2003).
I've read this years ago but had forgotten the astonishing figure of 200 lp/mm
for Ektar 25. Thanks for reminding me of it. It would be nice if Zeiss
could repeat the test with the new Ektar 100.
Ektar 25 managed to resolve 200 lp/mm.
Wow, isn't that great? You've really caught me by surprise. I'll shoot a roll of Ektar 100 on my next trip.
Velvia did 160 lp/mm. Portra 160VC 150
lp/mm. Portra 160NC 140 lp/mm. Ektachrome 100 VS recorded 130 lp/mm.
Not much in it.
Not much in it in terms of lp/mm, I agree, but when I also compare the
granularity of the films (not RMS directly, of course) and the overall
rendition of colours and textures, my observation is that transparency
film is noticeably better (comparing 160S to Astia, for
example). Nonetheless, I usually prefer negative film for portraits,
and I'm thrilled by the latest improvements and can't wait to try a
roll of Ektar 100.
But then add the effect of dynamic range you also
mentioned, and unless you are shooting 'flat' subjects, colour
negative film clearly is the better of any slide film.
A agree, which is why I use slide film for flat subjects such as
landscapes lit by morning and evening light and so on.
Velvia may indeed do a tiny bit better than Portra, but in a
smaller part of any typical scene.
For scenes that I'm interested in, I find Portra or any other negative
film inferior to Fuji slide film. But never mind. Let's use what we
like and use as much of it as we can afford, because that is what will
ultimately determine which films or processes will disappear and which
ones will stay. I'm pretty sure E-6 will stay, though. Nothing blows
your socks away as far as a nicely exposed slide.